The TI-99/4 was a less known and not very successful predecessor to the popular TI-99/4A computer.

Released in 1979, the 99/4 was TI's first entry into the home computer market and many expected it to be a hit since it was developed by a major semiconductor company. However, due to many factors such as FCC rejection of the TI's RF Modulator and the failure of the cheaper TMS 9985 chip, the price was significantly higher then average family was ready to pay and the computer never gained much popularity. It was discontinued in about a year since the introduction to market. Approximately 25,000 units were sold. It was replaced by the improved TI-99/4A console in 1981 which ended up selling somewhere around 3 million units.

The TI-99/4 has a chiclet keyboard with orange Shift and Enter keys. Plastic overlays were sold with some of the cartridges, which could be placed on the keyboard to show what functions the keys provided. Some cartridges required use of specialized functions, which made it necessary to package overlays with some of the titles. The TI-99/4 uses the same TMS 9900 CPU as the TI-99/4A, but has a different video chip - TMS 9918 instead of the updated TMS 9918A in the TI-99/4A (hence the "A" in its name).